Try Linux on a Mac without installing anything

A Mac starts from a USB stick if you hold the Option key while it powers on. Linux runs from the stick using your screen, keyboard and trackpad, touches nothing on the disk, and is gone the moment you restart without it.

Do this before you install anything. An hour with the real thing on your own Mac tells you whether the wifi connects, whether the trackpad feels right and whether you can live with the look of it. No review can tell you any of that.

What you need

A USB stick of 8 GB or more, which will be wiped. About an hour. An Intel Mac from 2008 or later, checked against the Mac guide. If your Mac is from 2018 to 2020 it has a T2 chip, and there are two extra steps in the section below. Do them first.

Make the stick in macOS

Go to linuxmint.com and download the Cinnamon edition. It’s a single file ending in .iso, around 3 GB.
Download Etcher from etcher.balena.io. It’s free, it’s what Mint’s own guide recommends on macOS, and it runs without installing anything.
Open Etcher. Choose the .iso file, choose your USB stick, and click Flash. macOS will ask for your password, because Etcher is about to write over an entire drive. Check that the drive it has chosen is the stick and nothing else.

macOS will complain when it’s done. A box appears saying the disk you inserted was not readable by this computer. That’s correct, since the stick is now in a format macOS doesn’t speak, and the button to press is Ignore. Don’t press Initialise, which would erase what you just made.

If your Mac has a T2 chip

Macs from 2018 to 2020 refuse to start from anything Apple hasn’t signed, which was the point of the chip. You switch that off once, in a tool Apple built for the purpose.

Shut the Mac down. Turn it on while holding Command and R together, and keep holding until you see the Apple logo. This is macOS Recovery.
From the Utilities menu at the top of the screen, choose Startup Security Utility, and type your password when asked.
Under Secure Boot, choose No Security. Under Allowed Boot Media, choose Allow booting from external or removable media.
Restart.

The t2linux project suggests setting a firmware password in that same tool, so a stranger with a USB stick can’t use the door you’ve just opened. It’s a good suggestion.

A T2 Mac also needs a different stick. The standard Mint download can’t see the Mac’s disk, keyboard or trackpad, because all three sit behind the T2. The t2linux volunteers publish a version of Mint with those pieces built in, at github.com/t2linux/T2-Mint, and it’s the one to flash in Etcher. At the time of writing it’s built on Mint 21.3, which is a year behind the current release and still supported until 2027.

Start from the stick

Shut the Mac down fully. Not sleep.
Plug the stick in. Press the power button and immediately hold the Option key, which some keyboards label Alt. Keep holding until a row of disk icons appears.
Click the one labelled EFI Boot. It has an orange icon and it’s the stick. On a T2 Mac it may be the only choice other than Macintosh HD.
A text menu appears with Start Linux Mint at the top. Press Enter, or wait.

A minute later you’re looking at a desktop with a menu in the bottom left and a clock in the bottom right. This is the live session. Everything you do here evaporates on restart, so poke at things freely.

What to test while you’re in there

Wifi first. Click the network icon near the clock. On many Macs there’s nothing to click, because the Broadcom chip Apple used has no driver on the stick. That’s expected, and it doesn’t mean your Mac has failed. The install guide fixes it in two clicks once Mint is on the disk. For the test, an Ethernet adapter or your phone on a USB cable gets you online. Or skip the internet for now.

Then the parts that matter day to day. Play a video, any video, and listen for sound. Press the brightness keys and the volume keys. The webcam needs an app to show it, and the stick doesn’t carry one, so that test waits until after the install. Close the lid, count to thirty, open it, and check the Mac wakes up. Put an SD card in if you own one. Two-finger scroll on the trackpad and see whether it goes the direction you expect, because Mint’s default is the opposite of Apple’s and it’s one setting to flip.

On a T2 Mac, expect the webcam to show nothing. Nobody has got it working under Linux and the t2linux state page says so. If video calls are your life, that’s the moment to decide whether an external webcam is an acceptable trade.

Whatever works from the stick will work once Mint is installed. The parts that didn’t are now specific things to search for, with your Mac’s model name and the word Mint.

Getting back to macOS

Click the menu, then the power icon, then Restart. Pull the stick out when the screen goes black. The Mac starts into macOS with the same files and the same wallpaper.

If you liked what you saw, the next step is backing up your files, and then installing Mint beside macOS.